You can definitely write some pure JS apps on iOS and bypass once for all the AppStore review process but you have to keep in mind that the JS runtime does not

You can definitely write some pure JS apps on iOS and bypass once for all the AppStore review process but you have to keep in mind that the JS runtime does not have yet access to all the API provided by the OS underneath. Here a a few things & there are many more that you will not be able to access from JS: - camera/video - photo library - address book - embedding a smooth map view: you can get google maps to appear but it will not be as smooth as the native MapKit control - all the goodness of CoreAnimation but the CSS animation on iOS made tremendous progress in each release - speed: even if with iOS 4.3 and the Nitro engine JS is faster, the compiled Objective-C / C / C++ will most likely be faster - re-use various existing runtime library (Facebook Connect/ DropBox / ...) Please do nit think that I don't believe in pure web app on iOS or other device. Some app can fit well the model abd make perfect sense to do as such, but I will strongly recommend that before comitting to a 100% web app, check that all the features you want to achieve are doable through JavaScript/CSS